BFDREEarly.cc

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/*
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/**
 * @file BFDREEarly.cc
 *
 * Definition of BFDREEarly class
 *
 * Performs a dead-result elimination after an early bypass.
 *
 * @author Heikki Kultala 2014-2020(heikki.kultala-no.spam-tuni.fi)
 * @note rating: red
 */
 
#include "BFDREEarly.hh"
#include "DataDependenceGraph.hh"
#include "BF2Scheduler.hh"
#include "Machine.hh"
 
bool
BFDREEarly::operator()() {
 
    if (!sched_.killDeadResults() && !targetMachine().alwaysWriteResults()) {
        return false;
    }
 
    if (ddg().resultUsed(mn_)) {
        return false;
    }
 
    // Take the predecssors of the dre'd src because their
    // antideps may change
    DataDependenceGraph::NodeSet pred = ddg().predecessors(mn_);
 
    createdEdges_ = ddg().copyDepsOver(mn_, true, false);
    ddg().dropNode(mn_);
    sched_.nodeAndCopyKilled(mn_);
 
    // now mark antideps sources to be notified
    for (auto n: pred) {
        mightBeReady(*n);
    }
 
    return true;
}